1. Field of the Invention
The present invention relates to a method for the automated control of a technical installation having a plurality of installation components, which are interconnected by data transmission to carry out process steps.
In particular, in the present invention is related to a method for automated control, which is adopted to carry out the following steps: generating by the central control device control commands while considering process control signals which are sent to the central control device and feeding the control commands to the installation components, where the process control signals generated in a mobile operator unit are wirelessly transmitted to interfaces and are forwarded by these interfaces to the control device.
2. Description of Related Art
In technical installations provided to carry out relatively complex technical processes, a plurality of installation components may need to interact with each other in a coordinated manner. For an automated process management or control, a technical installation with a plurality of installation components is usually assigned a process control system or an automation system, in which control commands for the individual installation components are typically output by a central control device. This central control device ensures that the mode of operation and the operating status of each installation component are properly coordinated with the other installation components with respect to the predefined process flow of the entire installation. The central control device, on the input side, is usually connected to a plurality of sensors for detecting the respective operating statuses of the individual installation components and, on the output side, is suitably connected to the installation components to transmit the control commands.
To enable the operator personnel to intervene in the process flow of the technical installation, e.g., to appropriately control the actual process flow in view of possibly varying process goals or to enable state monitoring or emergency overrides with respect to specified safety requirements, the respective central control device assigned to the technical installation is usually further connected to control or operator units on the input side. These operator units are used by the operator personnel to enter appropriate operator commands to control the process. Each operator unit can be processor-controlled and permanently installed in a fixed location, e.g., in the form of a personal computer (PC) or a control console.
In the more recent automated process control concepts, however, it may be desirable to provide the operator personnel with suitable mobile access to influence the process flow. To provide the operator personnel with mobile access, the operator units or at least a portion thereof may be configured as mobile units. These mobile units communicate with the central control device through a wireless connection, e.g., a radio link, to transmit process control signals. Wireless networking technology, as implemented, for example, in so-called wireless LANs (WLANs), may be used to wirelessly connect panels, laptops or web pads as mobile operator units to the central control device.
In addition to the process control signals considered when generating the control commands, other communication parameters, such as diagnostic parameters, may be wirelessly transmitted, including from the central control device to the respective mobile operator unit.
Because of the mobility of closed-loop and open-loop control, diagnostics or visualization of the individual process steps or states, such a configuration of an automation system or process control system affords a high degree of flexibility in the process control of the technical installation.
However, the mobility achieved for the operator personnel for interventions in the process flows of the technical installation has the risk that the operator will move relatively far away from the installation component or the portion of the machinery that needs to be controlled in the respective process state. Consequently, direct observation of the installation component to be controlled is not guaranteed during the intervention in the process flow. As a result, if incorrect operations occur or if changes in the process state can initially be observed only directly at the respective installation component, the absence of direct visual contact could cause an operator response that is inappropriate for the installation situation as a whole. Furthermore, if the respective mobile operator unit is physically too remote from the currently used interface, the transmission quality can be affected, which in turn can cause transmission errors and therefore process errors.
To avoid these problems and to provide a particularly high degree of operational safety through proper and situationally appropriate operation of the automation system of the technical installation, it is desirable to limit the release of the access from a mobile operator unit to specific installation components. To limit the release of the access from a mobile operator unit, the German Laid Open Publication DE 101 107 76 A1, which is incorporated herein by reference, discloses a method using mobile operator units, where the respective unit is first assigned to the installation component to be controlled before an operator's intervention in the process flow of an installation component is released. An intervention in the process is released only after the installation component in which the respective intervention in the process flow is to occur has been properly assigned to the mobile operator unit being used at the time.
From the article by Günter Herkommer titled “Die Kombilösung” (The Multi-Purpose Solution), Computer & Automation, Volume 01/2002, pp. 44–47, which is incorporated herein by reference, it is known to release interventions in the process flows of a technical installation from mobile operator units as a function of the current location of the operator in relation to the installation components.
In both of these systems (the system described in the German Laid Open Publication DE 101 107 76 A1 and the system described in the article by Günter Herkommer titled “Die Kombilösung” (The Multi-Purpose Solution), Computer & Automation, Volume 01/2002, pp. 44–47), to detect the operator's location, a separate positioning system is provided. This system can, for example, be an infrared-based system, particularly to avoid affecting other functional flows. As a result, however, these automation systems or process control systems are comparatively complex.